Apparatus and method for manufacturing porous glass preform for optical fiber

Abstract

A manufacturing method of a porous glass preform for optical fiber by depositing glass microparticles on a starting member, including supplying a vaporizer with organic silicon compound raw material in a liquid state and a carrier gas; in the vaporizer, mixing and vaporizing the organic silicon compound raw material in a liquid state and the carrier gas to convert the organic silicon compound raw material and the carrier gas into a raw material mixed gas; supplying a burner with the raw material mixed gas and a combustible gas, combusting the raw material mixed gas and the combustible gas in the burner, and ejecting SiO 2 microparticles generated by the combustion from the burner; and depositing the SiO 2 microparticles ejected from the burner on the starting member by repeatedly moving a single body, in which the vaporizer and the burner are synchronized, parallel to the starting member in a longitudinal direction thereof.

What is claimed is: 
     
         1 . A manufacturing method of a porous glass preform for optical fiber by depositing glass microparticles on a starting member, the manufacturing method comprising:
 supplying a vaporizer with organic silicon compound raw material in a liquid state and a carrier gas, the organic silicon compound raw material having a boiling point of less than or equal to 300° C.;   in the vaporizer, mixing together and vaporizing the organic silicon compound raw material in the liquid state and the carrier gas to convert the organic silicon compound raw material and the carrier gas into a raw material mixed gas;   supplying, through a raw material gas pipe made of PTFE, a burner with the raw material mixed gas and a combustible gas, combusting the raw material mixed gas and the combustible gas in the burner, and ejecting SiO 2  microparticles generated by the combustion from the burner; and   depositing the SiO 2  microparticles ejected from the burner on the starting member by repeatedly moving the burner parallel to the starting member in a longitudinal direction thereof.   
     
     
         2 . The manufacturing method of a porous glass preform for optical fiber according to  claim 1 , wherein
 depositing the SiO 2  microparticles includes repeatedly moving the vaporizer together with the burner, in a synchronized mummer, parallel to the starting member in the longitudinal direction thereof.   
     
     
         3 . The manufacturing method of a porous glass preform for optical fiber according to  claim 1 , wherein
 the organic silicon compound raw material is selected from a group of octamethylcyclotetrasiloxane (OMCTS), hexamethyldisiloxane, hexamethylcyclotrisiloxane, decamethylcyclopentasiloxane, dodecamethylcyclohexasiloxane, trimethoxymethylsilane, and tetramethoxysilane.   
     
     
         4 . The manufacturing method of a porous glass preform for optical fiber according to  claim 1 , wherein
 the organic silicon compound raw material has a purity greater than or equal to 99% by mass.   
     
     
         5 . The manufacturing method of a porous glass preform for optical fiber according to  claim 1 , wherein
 an inert gas such as nitrogen, argon, or helium is used as the carrier gas in the raw material mixed gas.   
     
     
         6 . The manufacturing method of a porous glass preform for optical fiber according to  claim 5 , wherein
 oxygen is also mixed into the raw material mixed gas to be supplied to the burner.   
     
     
         7 . The manufacturing method of a porous glass preform for optical fiber according to  claim 1 , wherein
 oxygen or a mixed gas including oxygen and an inert gas is used as the carrier gas .   
     
     
         8 . The manufacturing method of a porous glass preform for optical fiber according to  claim 1 , further comprising:
 heating the carrier gas supplied to the vaporizer.   
     
     
         9 . The manufacturing method of a porous glass preform for optical fiber according to  claim 1 , wherein
 the raw material gas pipe is stored in a flexible mobile cable protection material, and   the depositing includes moving the burner while guiding the burner with a guide mechanism.   
     
     
         10 . The manufacturing method of a porous glass preform for optical fiber according to  claim 1 , further comprising:
 heating the raw material gas pipe.   
     
     
         11 . A manufacturing apparatus for manufacturing a porous glass preform for optical fiber, comprising:
 a burner adapted to deposit SiO 2  microparticles on a starting member while moving parallel thereto along a longitudinal direction of the starting member;   a vaporizer adapted to convert organic silicon compound raw material in a liquid state into a raw material gas in a gaseous state, the organic silicon compound raw material having a boiling point of less than or equal to 300° C.;   a raw material liquid pipe through which the organic silicon compound raw material is supplied to the vaporizer; and   a raw material gas pipe made of PTFE through which the raw material gas in the gaseous state is supplied from the vaporizer to the burner.   
     
     
         12 . The manufacturing apparatus for manufacturing a porous glass preform for optical fiber according to  claim 11 , wherein
 the vaporizer and the burner are arranged in a manner to be movable together.   
     
     
         13 . The manufacturing apparatus for manufacturing a porous glass preform for optical fiber according to  claim 11 , wherein
 the raw material liquid pipe is mobile in a manner to move following the burner.   
     
     
         14 . The manufacturing apparatus for manufacturing a porous glass preform for optical fiber according to  claim 11 , further comprising:
 a guide mechanism adapted to guide the movement of the burner; and   a mobile cable protection material that is flexible and adapted to store the raw material gas pipe.   
     
     
         15 . The manufacturing apparatus for manufacturing a porous glass preform for optical fiber according to  claim 11 , further comprising:
 a heater adapted to heat the raw material gas pipe.